1. The problem statement, all variables and given/known data A person who normally weighs 200 lbs is standing on a scale inside of an elevator. The elevator is moving downwards at a constant speed of 7.0 m/s and then begins to slow down at a rate of 4.9 m/s^2. Before the elevator begins to decelerate, the reading of the scale is ____, and while the elevator is slowing down, the scale reads: A. 200 lbs, 100 lbs. B. less than 200 lbs, 300 lbs C. less than 200 lbs, 100 lbs, D. 200 lbs, 300 lbs. E. 200 lbs, 200 lbs 2. Relevant equations F = ma 3. The attempt at a solution All a scale knows is the normal force being exerted on it. Initially there's no acceleration so weight is the same. That eliminates B and C. It then begins to decelerate at 4.9 m/s^2. I thought either which way acceleration is negative. Your velocity is going from being positive to less positive. F - mg = ma F = mg + ma F = 200 lbs (9.8 m/s^2 - 4.9 m/s^2) I know the units aren't right and my teacher said I wouldn't have to convert but I don't know why I would ADD 4.9 m/s^2. I thought the problem was just giving the magnitude of the deceleration.